The present invention is related to energy management systems, including the generation, storage, and transmission systems for lighter-than-air (LTA) vehicles.
Previous solutions to airship energy generation and storage have used ‘stand-alone’ power systems: i.e. discrete batteries or regenerative fuel cell systems, discrete solar panels, discrete electrical power distribution cables. Conventional airship power system design includes a solar array at the top of the airship, which is accessible to direct sunlight, and the energy storage system (batteries or regenerative fuel cells) at the bottom of the airship, due to airship stability requirements. This architecture requires a significant mass of electrical conductors to carry the power from the solar array to the energy storage system. This conductor mass can amount to hundreds or even thousands of pounds. Additional cables are then required to distribute power, either directly from the solar array, or from the energy storage system, to the main electrical loads such as propulsors and blowers, often located at widely dispersed locations on the airship. These cable runs also add significant weight.
Generation, transmission and storage of energy for a long-duration airship requires extremely heavy components, and has significant inefficiencies. This weight and inefficiency significantly impacts the potential capability of projected long-duration airships. A fundamental flaw is the attempt to impose a satellite-power architecture (i.e. solar regenerative power) onto a significantly larger vehicle, with significantly higher power requirements and much more variable array orientation. A more efficient system, specifically designed to be organically incorporated into the fundamental lighter-than-air structure, should be able to significantly reduce the weight and improve overall performance.
A regenerative power system, i.e., a power system able to extract energy from the environment rather than carrying consumable fuel, is a key enabling technology for persistent flight of lighter-than-air vehicles. Any means to increase the specific power (Watts/kilogram) and specific energy (Watt-hours/kilogram) of the power system will have a positive impact on airship performance.
The storage of large quantities of hydrogen and oxygen gas required for nighttime energy production comes with a very significant weight impact on the airship. Therefore, it would be desirable to store or provide hydrogen and oxygen, particularly for lighter-than-air systems, in ways that do not result in excessive weight for the system. In the case of hydrogen, current state of the art only enables a 15% weight efficient storage.